Universality of flux quantum in an s-wave superconducting ring

Abstract

Abstract A problem of the crossover of the flux periodicity in an s-wave superconducting ring whether a period hc/e arises instead of hc/2e is studied in the basis of the linearized Ginzburg-Landau equation for the order parameter. We analyze the behavior of the Little-Parks oscillations for a one-dimensional superconducting ring threaded by an external magnetic flux and find the period of the magnetic flux is strictly hc/2e independent of the radius of the ring. The obtained result shows the universality of a superconducting flux quantum.